Fatty acid-binding protein 2 Ala54Thr genotype is associated with insulin resistance and leptin levels changes after a high monounsaturated fat diet in obese non-diabetic patients

Abstract

It has been found that the expression of fatty acid binding protein 2 (FABP2) mRNA is under dietary control. This polymorphism was associated with high insulin resistance, and fasting insulin concentrations. The aim of our study was to investigate the influence of Thr54 polymorphism in the FABP2 gene on metabolic response, weight loss and serum adipokine levels secondary to a high monounsaturated fat hypocaloric diet. A sample of 122 obese patients was analyzed in a prospective way. The hypocaloric diet had 1342 kcal, 46.6% of carbohydrates, 34.1% of lipids and 19.2% of proteins, with a 67.5% of monounsaturated fats, and lasted 3 months. Fifty-five patients (45.1%) had the genotype Ala54/Ala54 (wild group) and 67 (64.9%) patients a mutant genotype, Ala54/Thr54 (54 patients, 44.3%) or Thr54/Thr54 (13 patients, 10.7%). In wild group, body mass index (-1.5±1.2 kg/m2), weight (-4.1±3.6 kg), fat mass (-3.6±3.3 kg), waist circumference (-4.9±2.9 cm), insulin (-1.7±3.6 mUI/l), homeostasis model assessment of insulin resistance (HOMA-IR) (-0.6±1.8 units) and leptin levels decreased (-7.6±7.1 ng/ml). In mutant group, anthropometric parameters improved, without changes in biochemical parameters. Carriers of Thr54 allele have a different response than wild type obese, with a lack of decrease of insulin levels, leptin levels and HOMA-IR.